90
-12. The newsstand had 90 copies at the beginning of the day
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78
Answer:
A i think
Step-by-step explanation:
Answer:
tbh i like the first one its so simple but like so nice at the same time
Recall that A = 1/2bh.
We are given that h = 4+2b
So, putting it all together:
168 = 1/2 b(4+2b)
168 = 1/2(4b + 2b^2)
168 = 2b + b^2
b^2 + 2b - 168 = 0.
Something that multiplies to -168 and adds to 2? There's a trick to this.
Notice 13^2 = 169. So, it's more than likely in the middle of the two numbers we're trying to find. So let's try 12 and 14. Yep. 12 x 14 = 168. So this factors into (b+14)(b-12) So b = -14 or b =12. Is it possible to have a negative length on a base? No. So 12 must be our answer.
Let's check this. If 12 is our base, then according to our problem, 2*12 + 4 would be our height... or 28. so what is 12 * 28 /2?
196. Check.
Hope this helped!
Answer:
To express the sum of two numbers using distributive property, we factor out the highest common factor (HCF) of the two numbers (i.e. the greatest number that can divide the two numbers without remainder)
28 = 2 x 2 x 7
42 = 2 x 3 x 7
The HCF of 28 and 42 is given by 2 x 7 = 14
Therefore, we express 28 + 42 using distributive property thus: 14(2 + 3)
