How do you solve 6h^2+17h+12=0?

2 Answers
May 20, 2015

6h^2 + 17h +12 = 0

We can Split the Middle Term of this equation to factorise it and then find the solution for the equation

In this technique, if we have to factorise an expression like ah^2 + bh + c, we need to think of 2 numbers such that:
N_1 xx N_2 = a xx c = 6 xx 12 = 72
and
N_1 +N_2 = b = 17

After trying out a few numbers we get N_1 = 9 and N_2 =8
9 xx 8 = 72, and 9 +8 = 17

6h^2 + 17h +12 = 6h^2 + 9h +8h +12
= 3h (2h + 3) + 4(2h + 3)
= (3h +4) (2h + 3)
the solution for the equation is :
color(blue)h=-4/3
color(blue)h= -3/2

May 20, 2015

The answer is h=-3/2, -4/3

Problem: Solve 6h^2+17h+12=0 .

Multiply 6 times 12 to get 72.
Find two numbers that when multiplied equal 72 and when added equal 17.
Numbers 8 and 9 meet the criteria.
Write the equation substituting 8h and 9h for 17h.

6h^2+8h+9h+12=0

Separate the first two terms from the second two terms.

(6h^2+8h)+(9h+12)

Factor out the GCF from both sets of terms.

2h(3h+4)+3(3h+4)=0

Factor out the GCF (3h+4) .

(3h+4)(2h+3)=0

Solve for h.

3h+4=0

3h=-4

h=-4/3

2h+3=0

2h=-3

h=-3/2

h=-3/2, -4/3