Help me solve this problem from kahn academy

Type the correct answer in the box. consider the system of linear equations below. rewrite one of the two equations above in the form ax + by = c, where a, b, and c are constants, so that the sum of the new equation and the unchanged equation from the original system results in an equation in one variable.

What will be the end result for the taxpayer who filed his federal income tax return using the 1040ez form shown belowa he'll owe $173b he'll receive a refund of $173c he'll owe $3921d he'll receive a refund of $3921

Crickets can jump with a vertical velocity of up to 14 ft/s. which equation models the height of such a jump, in feet, after t seconds? h(t) = –16t2 + v0t + h0 h(t) = –16t2 + v0t + 14 h(t) = –16t2 + 14t h(t) = –16t2 + 14t + 14 what is the maximum height the cricket reaches? round to the nearest thousandth. h = feet