Solve for w
w=-5
w = \frac{3}{2} = 1\frac{1}{2} = 1.5
Share
Copied to clipboard
\left(w-2\right)\left(w+7\right)\times 2-\left(w-2\right)\times 3=-7
Variable w cannot be equal to any of the values -7,2 since division by zero is not defined. Multiply both sides of the equation by \left(w-2\right)\left(w+7\right), the least common multiple of w+7,\left(w-2\right)\left(w+7\right).
\left(w^{2}+5w-14\right)\times 2-\left(w-2\right)\times 3=-7
Use the distributive property to multiply w-2 by w+7 and combine like terms.
2w^{2}+10w-28-\left(w-2\right)\times 3=-7
Use the distributive property to multiply w^{2}+5w-14 by 2.
2w^{2}+10w-28-\left(3w-6\right)=-7
Use the distributive property to multiply w-2 by 3.
2w^{2}+10w-28-3w+6=-7
To find the opposite of 3w-6, find the opposite of each term.
2w^{2}+7w-28+6=-7
Combine 10w and -3w to get 7w.
2w^{2}+7w-22=-7
Add -28 and 6 to get -22.
2w^{2}+7w-22+7=0
Add 7 to both sides.
2w^{2}+7w-15=0
Add -22 and 7 to get -15.
w=\frac{-7±\sqrt{7^{2}-4\times 2\left(-15\right)}}{2\times 2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 2 for a, 7 for b, and -15 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
w=\frac{-7±\sqrt{49-4\times 2\left(-15\right)}}{2\times 2}
Square 7.
w=\frac{-7±\sqrt{49-8\left(-15\right)}}{2\times 2}
Multiply -4 times 2.
w=\frac{-7±\sqrt{49+120}}{2\times 2}
Multiply -8 times -15.
w=\frac{-7±\sqrt{169}}{2\times 2}
Add 49 to 120.
w=\frac{-7±13}{2\times 2}
Take the square root of 169.
w=\frac{-7±13}{4}
Multiply 2 times 2.
w=\frac{6}{4}
Now solve the equation w=\frac{-7±13}{4} when ± is plus. Add -7 to 13.
w=\frac{3}{2}
Reduce the fraction \frac{6}{4} to lowest terms by extracting and canceling out 2.
w=-\frac{20}{4}
Now solve the equation w=\frac{-7±13}{4} when ± is minus. Subtract 13 from -7.
w=-5
Divide -20 by 4.
w=\frac{3}{2} w=-5
The equation is now solved.
\left(w-2\right)\left(w+7\right)\times 2-\left(w-2\right)\times 3=-7
Variable w cannot be equal to any of the values -7,2 since division by zero is not defined. Multiply both sides of the equation by \left(w-2\right)\left(w+7\right), the least common multiple of w+7,\left(w-2\right)\left(w+7\right).
\left(w^{2}+5w-14\right)\times 2-\left(w-2\right)\times 3=-7
Use the distributive property to multiply w-2 by w+7 and combine like terms.
2w^{2}+10w-28-\left(w-2\right)\times 3=-7
Use the distributive property to multiply w^{2}+5w-14 by 2.
2w^{2}+10w-28-\left(3w-6\right)=-7
Use the distributive property to multiply w-2 by 3.
2w^{2}+10w-28-3w+6=-7
To find the opposite of 3w-6, find the opposite of each term.
2w^{2}+7w-28+6=-7
Combine 10w and -3w to get 7w.
2w^{2}+7w-22=-7
Add -28 and 6 to get -22.
2w^{2}+7w=-7+22
Add 22 to both sides.
2w^{2}+7w=15
Add -7 and 22 to get 15.
\frac{2w^{2}+7w}{2}=\frac{15}{2}
Divide both sides by 2.
w^{2}+\frac{7}{2}w=\frac{15}{2}
Dividing by 2 undoes the multiplication by 2.
w^{2}+\frac{7}{2}w+\left(\frac{7}{4}\right)^{2}=\frac{15}{2}+\left(\frac{7}{4}\right)^{2}
Divide \frac{7}{2}, the coefficient of the x term, by 2 to get \frac{7}{4}. Then add the square of \frac{7}{4} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
w^{2}+\frac{7}{2}w+\frac{49}{16}=\frac{15}{2}+\frac{49}{16}
Square \frac{7}{4} by squaring both the numerator and the denominator of the fraction.
w^{2}+\frac{7}{2}w+\frac{49}{16}=\frac{169}{16}
Add \frac{15}{2} to \frac{49}{16} by finding a common denominator and adding the numerators. Then reduce the fraction to lowest terms if possible.
\left(w+\frac{7}{4}\right)^{2}=\frac{169}{16}
Factor w^{2}+\frac{7}{2}w+\frac{49}{16}. In general, when x^{2}+bx+c is a perfect square, it can always be factored as \left(x+\frac{b}{2}\right)^{2}.
\sqrt{\left(w+\frac{7}{4}\right)^{2}}=\sqrt{\frac{169}{16}}
Take the square root of both sides of the equation.
w+\frac{7}{4}=\frac{13}{4} w+\frac{7}{4}=-\frac{13}{4}
Simplify.
w=\frac{3}{2} w=-5
Subtract \frac{7}{4} from both sides of the equation.
Examples
Quadratic equation
{ x } ^ { 2 } - 4 x - 5 = 0
Trigonometry
4 \sin \theta \cos \theta = 2 \sin \theta
Linear equation
y = 3x + 4
Arithmetic
699 * 533
Matrix
\left[ \begin{array} { l l } { 2 } & { 3 } \\ { 5 } & { 4 } \end{array} \right] \left[ \begin{array} { l l l } { 2 } & { 0 } & { 3 } \\ { -1 } & { 1 } & { 5 } \end{array} \right]
Simultaneous equation
\left. \begin{cases} { 8x+2y = 46 } \\ { 7x+3y = 47 } \end{cases} \right.
Differentiation
\frac { d } { d x } \frac { ( 3 x ^ { 2 } - 2 ) } { ( x - 5 ) }
Integration
\int _ { 0 } ^ { 1 } x e ^ { - x ^ { 2 } } d x
Limits
\lim _{x \rightarrow-3} \frac{x^{2}-9}{x^{2}+2 x-3}