\left\{ \begin{array} { l } { \frac { 2 x - 1 } { 5 } + \frac { 3 y 2 } { 4 } = 2 } \\ { \frac { 3 x + 1 } { 5 } - \frac { 3 y + 2 } { 4 } = 0 } \end{array} \right.
Solve for x, y
x=-\frac{15y_{2}}{8}+\frac{11}{2}
y=-\frac{3y_{2}}{2}+4
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4\left(2x-1\right)+5\times 3y_{2}=40
Consider the first equation. Multiply both sides of the equation by 20, the least common multiple of 5,4.
8x-4+5\times 3y_{2}=40
Use the distributive property to multiply 4 by 2x-1.
8x-4+15y_{2}=40
Multiply 5 and 3 to get 15.
8x+15y_{2}=40+4
Add 4 to both sides.
8x+15y_{2}=44
Add 40 and 4 to get 44.
8x=44-15y_{2}
Subtract 15y_{2} from both sides.
4\left(3x+1\right)-5\left(3y+2\right)=0
Consider the second equation. Multiply both sides of the equation by 20, the least common multiple of 5,4.
12x+4-5\left(3y+2\right)=0
Use the distributive property to multiply 4 by 3x+1.
12x+4-15y-10=0
Use the distributive property to multiply -5 by 3y+2.
12x-6-15y=0
Subtract 10 from 4 to get -6.
12x-15y=6
Add 6 to both sides. Anything plus zero gives itself.
8x=44-15y_{2},12x-15y=6
To solve a pair of equations using substitution, first solve one of the equations for one of the variables. Then substitute the result for that variable in the other equation.
8x=44-15y_{2}
Pick one of the two equations which is more simple to solve for x by isolating x on the left hand side of the equal sign.
x=-\frac{15y_{2}}{8}+\frac{11}{2}
Divide both sides by 8.
12\left(-\frac{15y_{2}}{8}+\frac{11}{2}\right)-15y=6
Substitute \frac{11}{2}-\frac{15y_{2}}{8} for x in the other equation, 12x-15y=6.
-\frac{45y_{2}}{2}+66-15y=6
Multiply 12 times \frac{11}{2}-\frac{15y_{2}}{8}.
-15y=\frac{45y_{2}}{2}-60
Subtract 66-\frac{45y_{2}}{2} from both sides of the equation.
y=-\frac{3y_{2}}{2}+4
Divide both sides by -15.
x=-\frac{15y_{2}}{8}+\frac{11}{2},y=-\frac{3y_{2}}{2}+4
The system is now solved.
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}