Square roots and squaring are always nonlinear.
2.75 * 12 = 33.
If the Sanchez family is using 2 3/4 (or 2.75) tubes of toothpaste and there are 12 months in a year, we use the equation above and get 33 as our answer.
Answer:
$3,000 invested at 6%
$7,000 invested at 10%
Step-by-step explanation:
Maria had total $10,000 to invest.
Let x be the amount that Maria invested initially at 6% interest rate.
0.06x
Then she invested the remaining amount at 10% interest rate.
0.10(10,000 - x)
She received a total of $880 in interest.
0.06x + 0.10(10,000 - x) = 880
0.06x + 1000 - 0.10x = 880
-0.04x = 880 - 1000
-0.04x = -120
0.04x = 120
x = 120/0.04
x = $3,000
This is the amount that Maria invested initially at 6% interest rate.
The remaining amount is
10,000 - 3,000
$7,000
This is the remaining amount that she invested at 10% interest rate.
In this case, since one equation is in the form of x=, substitution would be best for this problem. Simply plug in 4y + 8 in place of x in the second equation, solve for y, then plug that value into the first equation to find x.
