Question 238172
sqrt5x+21=x+3 square both side.
5x+21=x^2+6x+9
x^2+6x-5x+9-21=0
x^2+x-12=0
(x+4)(x-3)=0
x+4=0
x=-4 ans.
x-3=0
x=3 ans.
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Factor completely
175w^2+490wp+343p^2
7(25w^2+70wp+49p)
7(5w+7p)^2 ans.