Solve {l}{0.65x+0.9y=55}{x+4=130}

$$\left. \begin{array} { l } { 0.65 x + 0.9 y = 55 } \\ { x + 4 = 130 } \end{array} \right.$$

Solve for x, y

$$x=126$$

$$y = -\frac{269}{9} = -29\frac{8}{9} \approx -29.888888889$$

Solution Steps

Consider the second equation. Subtract 4 from both sides.

$$x=130-4$$

Subtract 4 from 130 to get 126.

$$x=126$$

Consider the first equation. Insert the known values of variables into the equation.

$$0.65\times 126+0.9y=55$$

Multiply 0.65 and 126 to get 81.9.

$$81.9+0.9y=55$$

Subtract 81.9 from both sides.

$$0.9y=55-81.9$$

Subtract 81.9 from 55 to get -26.9.

$$0.9y=-26.9$$

Divide both sides by 0.9.

$$y=\frac{-26.9}{0.9}$$

Expand \frac{-26.9}{0.9} by multiplying both numerator and the denominator by 10.

$$y=\frac{-269}{9}$$

Fraction \frac{-269}{9} can be rewritten as -\frac{269}{9} by extracting the negative sign.

$$y=-\frac{269}{9}$$

The system is now solved.

$$x=126 y=-\frac{269}{9}$$