Answer asap only if you know solve by elimination

3x + 2y = 21 x - 4y = -7

show work plz and thx

Select the lengths in centimeters that would form a right triangle

What is the ordered pair of m’ after point m (5, 6) is rotated 90° counterclockwise?

If (x + 8) is a factor of f(x), which of the following must be true? both x = –8 and x = 8 are roots of f(x). neither x = –8 nor x = 8 is a root of f(x). f(–8) = 0 f(8) = 0