<span>answer
A) (-5,-49),(-2,-22),(3,23)
</span>when x = - 5 ; y=9x-4 = 9(-5) -4 = -49
when x = - 2 ; y=9x-4 = 9(-2) -4 = -22
when x = 3 ; y=9x-4 = 9(3) -4 = 23
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.
Given:
The figure of two quadrilaterals.
In 
In 
To find:
Whether the figures are congruent, similar or neither.
Solution:
Ratio of corresponding sides are:
Similarly,
And,
Clearly, 
.
All corresponding sides are not proportional.
Therefore, the figures are neither similar nor congruent. Hence, third option is correct.
