Answer:
The answer is 27
Step-by-step explanation:
The reason being, you can solve this 2 ways.
1) Combine like terms, 7a-4a = 3a.
Now just substitute (a=9) into 3a.
3 * (9) = 27.
2) Or just substitute a = 9 into the original expression.
7 * (9) - 4 * (9)
= 63 - 36 = 27
Well, if both Alexis and Tara mine salt for 40 hours... they'd have mine 1,000 pounds of salt. Is this what you were looking for?
BBBBBBBBBBBBBBBBBBBbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
The sum of 14 and a number is 14+x
we know that this equals 17, so: 14+x=17.
Let's substract 14 from both sides:
x=17-14
x=3
so the number is 3.