Question

Simplify the following algebraic expression and find the value when a=5 and b=1
5[(-a)+(-2)]+2(2a-b)+4a-7

Answer 1

Dear Student,
$$\begin{gathered} 5\left[\left(-\mathrm{a}\right)+\left(-2\right)\right]+2\left(2\mathrm{a}-\mathrm{b}\right)+4\mathrm{a}-7 \\ =5\left[\left(-5\right)+\left(-2\right)\right]+2\left(2\times 5-1\right)+4\times 5-7\{\mathrm{putting}\mathrm{the}\mathrm{value}\mathrm{of}\mathrm{a}\mathrm{and}\mathrm{b}\} \\ =5\times \left(-7\right)+2\left(10-1\right)+20-7 \\ =-35+2\times 9+20-7 \\ =-35+18+20-7 \\ =38-42 \\ =-4 \end{gathered}$$
Regards