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.
I think you meant to write
(2 × 10⁶) × 0.00009
First, convert 0.00009 to scientific notation:
0.00009 = 9 × 10 ⁻⁵
Then
(2 × 10⁶) × 0.00009 = (2 × 10⁶) × (9 × 10 ⁻⁵)
… = (2 × 9) × (10⁶ × 10 ⁻⁵)
… = 18 × 10¹
… = 1.8 × 10²
Answer:<2 and <3 are the two angles that are exterior angles!
Step-by-step explanation:
Hope this helped!
<!> Brainliest is appreciated! <!>
Answer:
The simplest (and most commonly used) area calculations are for squares and rectangles. To find the area of a rectangle, multiply its height by its width. For a square, you only need to find the length of one of the sides (as each side is the same length) and then multiply this by itself to find the area.
-3 because if you add -3 to 3 you get 0
