Using the pictures above, which theorem, postulate or defintion supports each statement?

Which linear equations have an infinite number of solutions? check all that apply.  (x  –  3/7)  =  2/7(3/2x  –  9/14)8(x  +  2)  =  5x  –  1412.3x  –  18  =  3(–6  +  4.1x)(6x  +  10)  =  7(x  –  2)4.2x  –  3.5  =  2.1 (5x  +  8)

Given the two similar triangles, how do i find the missing length? if a=4, b=5, and b'=7.5 find a'

Aright triangle has an area of 21 m2. the dimensions of the triangle are increased by a scale factor of 4. what is the area of the new triangle