Answer:
1/125, 1/625, 1/3125
Step-by-step explanation:
a8=25*(1/5)^7=25/78125=1/3125
18 kg of 15% copper and 72 kg of 60% copper should be combined by the metalworker to create 90 kg of 51% copper alloy.
<u>Step-by-step explanation:</u>
Let x = kg of 15% copper alloy
Let y = kg of 60% copper alloy
Since we need to create 90 kg of alloy we know:
x + y = 90
51% of 90 kg = 45.9 kg of copper
So we're interested in creating 45.9 kg of copper
We need some amount of 15% copper and some amount of 60% copper to create 45.9 kg of copper:
0.15x + 0.60y = 45.9
but
x + y = 90
x= 90 - y
substituting that value in for x
0.15(90 - y) + 0.60y = 45.9
13.5 - 0.15y + 0.60y = 45.9
0.45y = 32.4
y = 72
Substituting this y value to solve for x gives:
x + y = 90
x= 90-72
x=18
Therefore, in order to create 90kg of 51% alloy, we'd need 18 kg of 15% copper and 72 kg of 60% copper.
Answer:
See below.
Step-by-step explanation:
Squaring a number means to multiply the number by itself.
For example, 3^2 means 3 * 3.
8^2 means 8 * 8.
(-6)^2 means (-6) * (-6).
In each case above, you see that the number that is squared is multiplied by itself.
In this case, (-4.5)^2, squaring the number -4.5, means multiply the number -4.5 by the number -4.5
(-4.5)^2 = (-4.5) * (-4.5)
Now we need to actually multiply -4.5 by -4.5
When you multiply a negative number by a negative number, the result is positive, so the product of -4.5 and -4.5 is a positive number. To find that number, you multiply 4.5 by 4.5
4.5 * 4.5 = 20.25
Therefore, (-4.5)^2 = 20.25
2 + 2 equals to 4
You can do it on the calculator too.
