Download 10x+3x

Solving equations using
factorisation
Example 1:x²+6x-16=0
Put the equation
equal to 0
8, -2
Find two number that add to make 6 and times to make 16:
Then put them into double brackets:
(x+8) (x-2)
Finally put both brackets equal to 0 and work out the
value of x
x+8=0 x= -8
X-2=0 x=2
Example 2:2x²-7x-15=0
-30
Then times the number in front of x²; 2, by the last number; -15 which
equals -30.
Two numbers that add to make -7 and times to make -30 are -10 and +3
Rewrite the formula as: 2x²-10x+3x-15=0
Treat the formula as two: 2x²-10x and
3x-15
2x²-10x
3x-15
Take out the biggest factor
that goes into both, 2x.
Take out the biggest factor
that goes into both again, 3.
Then we write it as 2x(x-5x)
So we write it as 3(x-5)
Put both equal to 0.
Then put together everything
outside the brackets and
2x(x-5)+3(x-5)=0
everything inside the brackets.
Both brackets should be
(2x+3)(x-5)=0
the same.
- 2x+3=0
X=-3
- X-5=0
X=5