Answer:
53lbs.
Step-by-step explanation:
If Kevin bought 3 20lbs. Bags of gravel he would have 60 lbs. of gravel. In the end he has 7 lbs. of gravel left he used 53 pounds.
Equations:
7+x=60 or 60-7=53 lbs.
<span> (x + 3) • (x - 12)
</span>
The first term is, <span> <span>x2</span> </span> its coefficient is <span> 1 </span>.
The middle term is, <span> -9x </span> its coefficient is <span> -9 </span>.
The last term, "the constant", is <span> -36 </span>
Step-1 : Multiply the coefficient of the first term by the constant <span> <span> 1</span> • -36 = -36</span>
Step-2 : Find two factors of -36 whose sum equals the coefficient of the middle term, which is <span> -9 </span>.
<span><span> -36 + 1 = -35</span><span> -18 + 2 = -16</span><span> -12 + 3 = -9 That's it</span></span>
Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above, -12 and 3
<span>x2 - 12x</span> + 3x - 36
Step-4 : Add up the first 2 terms, pulling out like factors :
x • (x-12)
Add up the last 2 terms, pulling out common factors :
3 • (x-12)
Step-5 : Add up the four terms of step 4 :
(x+3) • (x-12)
Which is the desired factorization
Final result :<span> (x + 3) • (x - 12)</span>
Multiply 18 pencils by 2 times colored markers and the answer will be 36
18 times 2 = 26