How do you solve a2+a30=0?

2 Answers
Jul 8, 2015

Solve y=x2+x30=0

Explanation:

y=x2+x30=0
Find 2 numbers knowing sum (-1) and product (-30). Roots have opposite signs.
Factor pairs of (-30) --> ....(-3, 10)(-5, 6). This sum is 1 = b.
Then the 2 real roots are the opposite: 5and6

Jul 8, 2015

Factor the trinomial into two binomials. Set each binomial equal to zero and solve for a.

Explanation:

a2+a30=0

Find two numbers that when added equal 1, and when multiplied equal 30.

The numbers 5 and 6 fit the pattern.

a2+a30=0 =

(a5)(a+6)=0

Set (a5) equal to zero and solve for a.

a5=0

a=5

Set (a+6) equal to zero and solve for a.

a+6=0

a=6

a=6,5