Ratio of Nickel to Zinc:
( 2/7 ) = ( Nickel /4.9)
Nickel = 1.4 lbs.
Ratio of Copper to Zinc:
( 9/7 ) = ( Copper /4.9)
Copper = 6.3 lbs.
Alloy = Zinc + Nickel +
Copper
Alloy = 4.9 lbs. + 1.4 lbs.
+ 6.3 lbs.
Alloy = 12.6 lbs.
Hope
this answer will be a good h<span>elp for you.</span>
Let the marks of the students in class 1 be
the average of these 12 marks is 90, so
which means
similarly, let
be the marks of the students in the second class,
so
which means
The 32 students averaged:
1,2,4,8 I might of missed something
The answer to this mathematical question would be "0.4x = 4.4". I simply subtracted 1.8x to both sides of the equation (following the subtraction property of equations) and then added 4.4 to both sides of the equation (following the addition property of equations). Thus, we arrive to the answer, 0.4x = 4.4.
A and D
Explanation: I did this problem in khan academy
