Question

Solve system of equations for a 3=10a+b 2=20a+b

Answer 1

this is in copy and paste form a = - 1/10 - 1.0

Answer 2

`\large\boxed{a=-(1)/(10)=0.1}`

Explanation:

`\left\{\begin{array}{ccc}3=10a+b\\2=20a+b&\text{change the signs}\end{array}\right\\\\\underline{+\left\{\begin{array}{ccc}3=10a+b\\-2=-20a-b\end{array}\right}\qquad\text{add both sides of the equations}\\.\qquad1=-10a\qquad\text{divide both sides by (-10)}\\.\qquad-(1)/(10)=a\Rightarrow a=-(1)/(10)`