ACT Math 3.3 Elementary Algebra
ACT Math Section: Elementary Algebra Drill 3, Problem 3. Solve for x.
|ACT Math||Elementary Algebra|
|ACT Mathematics||Elementary Algebra|
|Algebra||Solve equations and inequalities in one variable|
Use polynomial identities to solve problem
Use polynomial identities to solve problems
|Elementary Algebra||Solve quadratic equations by factoring|
Solving simple quadratic equations
|Foreign Language||Arabic Subtitled|
|One-Variable Equations and Inequalities||Solving Equations|
|Product Type||ACT Math|
What 2 numbers can be multiplied to get 8... and can also be added to get 6?
Well, the factors of 8 are 1 and 8; that won't work...
...what about 2 and 4? Ding ding ding!
So... 2 times 4 is 8... and 2 PLUS 4 is 6... so we can just rewrite the factored version as
The quantity x plus 2 times the quantity x plus 4... equals zero.
Now if either of these guys is 0, the whole equation is zero because zero times anything...
is zero. Yeah, it brings everyone else down to its level.
So if x is negative 2, this part is 0... and if x is negative 4, this part is 0.
x has to be one of those answers... and OUR answer here is either A or B... which is...
option D. Done