5.25 pounds of one alloy containing 45% copper and 36.75 pounds of 69% copper is used to make 42 pounds of 66% copper
<h3>What is an
equation?</h3>
An equation is an expression that shows the relationship between two or more variables and numbers.
Let x represent the amount of 45% copper and y represent the amount of 66% copper needed to make 42 pounds of a third alloy containing 66% copper. Hence:
x + y = 42 (1)
Also:
0.45x + 0.69y = 42(0.66) (2)
This gives:
x = 5.25, y = 36.75
5.25 pounds of one alloy containing 45% copper and 36.75 pounds of 69% copper is used to make 42 pounds of 66% copper
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I’m not entirely sure, but try Desmos or Symbolab calculators :)
Answer:
5
Step-by-step explanation:
Answer:
option (a) It will be closer to 30 than to 20
Step-by-step explanation:
Data provided in the question:
For sample 1:
n₁ = 10
variance, s₁² = 20
For sample 2:
n₂ = 15
variance, s₂² = 30
Now,
The pooled variance is calculated using the formula,
on substituting the given respective values, we get
or
= 26.0869
Hence,
the pooled variance will be closer to 30 than to 20
Therefore,
The correct answer is option (a) It will be closer to 30 than to 20
If (x+5) is a factor the equation will equal zero when x=-5 so
3(-5^2)+14(-5)+k=0
75-70+k=0
5+k=0
k=-5
