Find the value of the expression 4a to the fourth power - 2b squared +40 when a =2 and b=7

4a^4 -2b^2 +40
a=2
b=7
4(2)^4 -2(7)^2 +40
PEMDAS is what your gonna use to solve this you go from right to left

First is P which is parentheses which is none
second is E which stands for exponents
4(32)-2(49)+40
now MD multiply or divide
128-98+40
now add or subtract
30+40
last one 
70 this is your answer i hope