Question

Solve the expressions on the left when x=53x-10x^2-155x-21x+10-8

Answer 1

`\begin{gathered} \text{if x=5} \\ 3x-10=3(5)-10 \\ =15-10 \\ =5 \\ \\ \\ x^2-15=(5)^2-15 \\ =25-15 \\ =10 \\ \\ 5x-21=5(5)-21 \\ =25-21 \\ =4 \\ \\ \\ \\ x+10-8=5+10-8 \\ =15-8 \\ =7 \end{gathered}`