Answer:
10x² - 12
Step-by-step explanation:
4x² - 7 + 6x² - 5 (combine like terms)
10x² - 12
Answer:
- $8000 at 1%
- $2000 at 10%
Step-by-step explanation:
It often works well to let a variable represent the amount invested at the higher rate. Then an equation can be written relating amounts invested to the total interest earned.
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<h3>setup</h3>
Let x represent the amount invested at 10%. Then 10000-x is the amount invested at 1%. The total interest earned is ...
0.10x +0.01(10000 -x) = 280
<h3>solution</h3>
Simplifying gives ...
0.09x +100 = 280
0.09x = 180 . . . . . . . subtract 100
x = 2000 . . . . . . divide by 0.09
10000 -x = 8000 . . . . amount invested at 1%
<h3>1.</h3>
$8000 should be invested in the 1% account
<h3>2.</h3>
$2000 should be invested in the 10% account
What is being solved for is r.
If the number is y then the inequality is
twice the difference of y and 7=2(y-7)
at most- 20=less than or equal to
2(y-7)≤-20
