Rewrite in simplest terms: -2(5d-9f)+7f-10(-9f-7d)

John used linear combination to solve the system of equations shown. he did so by multiplying the first equation by -3 and the second equation by another number to eliminate the x-terms. what number did jonas multiply the second equation by? 4x-6y=23x+5y=11

Write an inequality for this description. - one fourth of the opposite of the difference of five and a number is less than twenty.

What rotation was applied to triangle def to create d’e’f’?