Answer:
Press A takes 10 hours to do a certain job. So Press A does (1/10)th of the job in an hour.
Press A and Press B, together do (1/2.5) or (4/10)th of the job in an hour.
So Press B does (4/10)-(1/10) = (3/10)th of the job in an hour. So Press B can do the job in (10/3) hours or 3 hour and 20 mins.
Check: A does (1/10)th and B does (3/10)th part of the job in an hour. A and B together will take (1/10)+(3/10) = 4/10th of the job in an hour. So they will complete the job in 10/4 = 2.5 hours. Correct.
Answer: Press B can do the job in 3 hour and 20 mins.
Step-by-step explanation:
First one :
10•5^2+4•-2^2=234
Second one :
-2(3•-2+-6)=24
<span>
−<span>2<span>(<span><span><span>(3)</span><span>(<span>−2</span>)</span></span>−6</span>)</span></span></span><span><span><span>
(<span>−2</span>)</span><span>(<span><span><span>(3)</span><span>(<span>−2</span>)</span></span>+<span>−6</span></span>)</span></span></span><span><span><span><span>
(<span>−2</span>)</span><span>(<span><span>(3)</span><span>(<span>−2</span>)</span></span>)</span></span>+<span><span>(<span>−2</span>)</span><span>(<span>−6</span>)</span></span></span></span><span>
<span>12+12</span></span><span><span>
24</span></span>
Last one :
2•-6(3•-6-5)
<span><span><span>
(2)</span><span>(<span>−6</span>)</span></span><span>(<span><span><span>(3)</span><span>(<span>−6</span>)</span></span>−5</span>)</span></span><span><span>
(<span><span>(2)</span><span>(<span>−6</span>)</span></span>)</span><span>(<span><span><span>(3)</span><span>(<span>−6</span>)</span></span>+<span>−5</span></span>)</span></span><span><span><span>
(<span><span>(2)</span><span>(<span>−6</span>)</span></span>)</span><span>(<span><span>(3)</span><span>(<span>−6</span>)</span></span>)</span></span>+<span><span>(<span><span>(2)</span><span>(<span>−6</span>)</span></span>)</span><span>(<span>−5</span>)</span></span></span><span>
216+60</span><span>
=276
Hoped I helped!</span>
First make the denominators the same = 4 5/20 - 3 12/20. Then make them improper fractions= 85/20-72/20= 13/20. Since that is already simplified the answer is 13/20.
Answer:
they should buy three more for the 5th grade to match the 4th grade
7.) (x, y) —> (1/2*x, 1/2*y)
