.
Please help me solve this problem: y=x^2-4x+10
y=2x+10
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
You are given a system of two equations
=
, (1)
=
. (2)
Since their left sides are identical, you can equate their right sides. Then you will get an equation
=
.
(Notice: it is the same as to substitute expression (2) into equation (1)).
Simplify:
=
.
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).