Answer: 137
Step-by-step explanation:
The given expression: [tex]7x^2 +8x-7[/tex]
We need to find the value of the expression when x=4.
So we just use the substitution property and substitute the value of x= 4 in the given expression , we get
[tex]7(4)^2+8(4)-7\\\\= 7(16)+32-7\\\\= 112+25\\\\=137[/tex]
Hence, the value of the expression at x=4 is 137.