X^2 -2X = 8
In "set to zero" form:
X^2 - 2X - 8 = 0
factoring:
(X + ?) * (X + ?) = 0
The two different numbers that are question marks must equal 8 when multiplying them together. This would suggest trying:
1, 8
or 2, 4
Since 8 is negative, one of the values must be negative.
The first factor is:
(X - 4)
So...
(X - 4) * (X + ?)
You can get the second factor easily from that.
Write each equation in standard form (set equal to zero). Then solve by factoring.
Example:
x²-2x=8
1 answer
1 answer