X + y = 40
y = 9x
x + 9x = 40 (substitute 9x for y in 1st equation)
10 x = 40
x = 4
4 + y = 40 (substitute 4 for x in 1st equation)
y = 36
Answer:
H
Step-by-step explanation:
It appears to be just a slope problem in disguise. Where if you find the slope, you find the density of nickel. In this case, it would be copper. The slope appears to be closer to 9, and if you take some of the points and divide it, like where it seems to cross 4 and 35, you would get an answer close to 9. Same with 40 and 4.5, you get 8.89. The only answer closest to that would be H
Answer:
B
Step-by-step explanation:
a^2+b^2=c^2
2^2+4^2=x^2
4+16=x^2
20=x^2
x=about 4.5
This is an example Estimate 3/7 + 5/9
Notice that 3/7 is close to 1/2 and 5/9 is also close to 1/2.
Therefore, an estimate for 3/7 + 5/9 is 1/2 + 1/2 = 1