Solve {l}{150-2b=140*2}{2a+2b=140*5}

$$\left. \begin{array} { l } { 150 - 2 b = 140 \times 2 } \\ { 2 a + 2 b = 140 \times 5 } \end{array} \right.$$

Solve for b, a

$$b=-65$$

$$a=415$$

Solution Steps

Consider the first equation. Multiply 140 and 2 to get 280.

$$150-2b=280$$

Subtract 150 from both sides.

$$-2b=280-150$$

Subtract 150 from 280 to get 130.

$$-2b=130$$

Divide both sides by -2.

$$b=\frac{130}{-2}$$

Divide 130 by -2 to get -65.

$$b=-65$$

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

$$2a+2\left(-65\right)=140\times 5$$

Multiply 2 and -65 to get -130.

$$2a-130=140\times 5$$

Multiply 140 and 5 to get 700.

$$2a-130=700$$

Add 130 to both sides.

$$2a=700+130$$

Add 700 and 130 to get 830.

$$2a=830$$

Divide both sides by 2.

$$a=\frac{830}{2}$$

Divide 830 by 2 to get 415.

$$a=415$$

The system is now solved.

$$b=-65 a=415$$