What is the value of the expression when a=3 and b=5?

8a+6 (2b-7)

Sub a = 3 and b = 5 into the expression above you get:

8*3+6 (2*5-7)

then use bedmas accordingly (this is the order of arithmetic operations)

8*3+6 (2*5-7)

=24+6 (10-7)

=24+6 (3)

=24+18

=42