SOLUTION: Please help me solve this problem: y=x^2-4x+10 y=2x+10

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Question 1020125: Please help me solve this problem: y=x^2-4x+10
y=2x+10

Answer by ikleyn(52786) About Me  (Show Source):
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Please help me solve this problem: y=x^2-4x+10
y=2x+10
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You are given a system of two equations

y = x%5E2-4x%2B10,    (1)
y = 2x%2B10.        (2)

Since their left sides are identical, you can equate their right sides. Then you will get an equation

2x+%2B+10 = x%5E2+-4x+%2B+10.

(Notice: it is the same as to substitute expression (2) into equation (1)).

Simplify:

x%5E2+-6x = 0.

Factor the left side polynomial. You will get

x*(x-6) = 0.

It has two roots: x=0 and x=6.
The corresponding y's are (from (2)):  y = 2x+10 = 2*0+10 = 10  and  y = 2*6+10 = 22, correspondingly.

Answer. There are two solutions: 1) (x,y) = (0,10)  and  2) (x,y) = (6,22).