The answer to the first part is 172 plants per row with a remainder of 3 plants
The answer to the second part is, Martin knows that 7 goes into 700 100 times, 7 goes into 490 70 times, and 7 goes into 17 twice with a remainder of 3. He then adds 100 70 and 2 together to get 172 with a remainder of 3.
Multiply each number across from another
Answer:
<u><em>The two numbers are 56 and 23.</em></u>
Step-by-step explanation:
Let the two numbers be A and B.
We are told that:
A+B = 79, and
2) 3A + 5B = 283
Rearrange the first expression to isolate A:
A = 79-B
Now use this value of B in the second expression:
3A + 5B = 283
3(79-B) + 5B = 283
237-3B + 5B = 283
2B = 46
B = 23
If B=23, we can find A from (1):
A+B = 79
A+23 = 79
A = 56
<u>CHECK:</u>
Does A+B = 79?
56 + 23 = 79? <u><em>YES</em></u>
Does 3A + 5B = 283?
3(56) + 5(23) = 283?
168 + 115 = 283? <u><em>YES</em></u>
Let x be the amount invested at 6%
840 = 0.06x + 0.075(2x)
840 = 0.06x + 0.15x
840 = 0.21x
x = 840/0.21
x = 4000
Therefore, she invests $4000 at 6% and $8000 at 7.5%
