Answer:
70[tex]x^{2}[/tex]+30x-140
Step-by-step explanation:
(7x+3) (10x-14)
70[tex]x^{2}[/tex]-98+30x-42
70[tex]x^{2}[/tex]+30x-42-98
x = 9
These are vertical angles, and thus the angles are equal.
7x + 3 = 10x - 24
Combining like terms, we get
27 = 3x, so that x must be 9.
