trintrin93 trintrin93
  • 12-01-2020
  • Mathematics
contestada

Solve the equation.
x2 − x − 12 = 0
A) x = 4
B) x = −3
C) x = −3 or x = 4
D) x = −4 or x = 3

Respuesta :

jingobobmh
jingobobmh jingobobmh
  • 12-01-2020

Answer:

C

Step-by-step explanation:

In this technique, if we have to factorise an expression like ax2+bx+c, we need to think of 2 numbers such that:

N1⋅N2=a⋅c=1⋅−12=−12

AND

N1+N2=b=−1

After trying out a few numbers we get N1=3 and N2=−4

3⋅−4=−12, and 3+(−4)=−1

x2−x−12=x2−4x+3x−12

x(x−4)+3(x−4)=0

(x+3)(x−4)=0

Now we equate the factors to zero.

x+3=0,x=−3

x−4=0,x=4

Answer Link

Otras preguntas

How can buoyant forces be measured?
7,000 is 10 times as much as what number?
Gracia and Jim were shooting free throws. Gracia made 4 out of 15 free throws. Jim missed 6 out of 16 free throws. Who made the free throw a greater fraction of
A playground is on the flat roof of a city school, hb = 6.20 m above the street below (see figure). The vertical wall of the building is h = 7.70 m high, to for
8 gal/h = ________ pt/min
A dragster going at 5 m/s north increases its velocity to 23 m/s north in 4 seconds. What is its acceleration during this time interval?
need help with this questiona milk man delivers 109865 bottles of milk a yearwrite the numbers of bottles toothe nearest 100the nearest 1000the nearest 10the ne
solve the equation. 8b – 7 = 7b – 2
How do you find prime numbers between 70 and 80
What is the difference between a pirate and a sailor