We can get two different equations from this:
3x = 18
and
3x = -18
So:
x = 6, x = -6
x = {6, -6}
The correct answer is A. Not only does $250 a week equal $1000 a month but the commission is also higher.
first job: $250wk = $1000 Month + .045 commission
= $12000 year + .045 commission
second job = $1800 Month + .03 commission
= $21600 year + .03 commission
commission based on sales of $1,000,000
1,000,000 times .045 = $45000
1,000,000 times .030 = $30000
FIRST JOB: $12,000 + $45,000 = $57,000
SECOND JOB: $21,600 + $30,000 = $51,600
The answer is definitely A.
When a quadratic equation ax^2+bx+c has a double root, the discriminant,
D=b^2-4ac=0
Here
a=2,
b=b,
c=18
and
D=b^2-4ac=b^2-4*2*18=0
solve for b
b^2-144=0
=> b= ± sqrt(144)= ± 12
So in order that the given equation has double roots, the possible values of b are ± 12.
First, do 40 - 12 = 28 (Subtract the change), then do 28 / 7 to get 4, so then we do the cans times 3 to see how many individual balls he has, which would be 12