16x2 = 49
factor the left side ?

Divide both sides by 16
X2=49/16
Square root of both sides
X=7/4

C. i believe it is (5×(-20))+(100×(0.7))

The question is kind of confusing. if it's asking how many variations of answers can you give. then do 4^5 for your answer.this would be something like the first question could be a and the 2nd c or first b next c etc. if you can, ask the teacher for a better confirmation of what it's asking. if i'm assuming correctly what it's asking, it's 625 different variations.