Question 596923
Plug in p = 4 (ie replace 'p' with 4) and evaluate


3(5p-1)-4(3p-7)


3(5*4-1)-4(3*4-7)


3(20-1)-4(12-7)


3(19)-4(5)


57-20


37



So 3(5p-1)-4(3p-7) = 37 when p = 4