Answer:
To do this you want to plug 3 in for d, so your equation will look like this
7(3)^2+10
In the order of PEMDAS you want to do exponents first, because there is no parentheses.
7*9+10 (3^2=9), next you want to multiply
63+10, lastly you want to add
63+10=73
73
Hope this helps ;)