5x+9z-x
5x-x+9z
4x+9z
Equivalent expression is asking for you to simplify by adding like terms and eliminatino parenthesis. Use the PEMDAS.
1/18.
.
P = p1 x p2 = 1/6 × 2/6 = 1/18
.
Prob of getting 3 is 1/6, and prob of getting different odd number ie 1 or 5 is 2/6.
1/2 and 2/3 because they are the biggest numbers.
9/10 and 5/6 because they are the smallest numbers.
ANSWER
Find out the how many pounds of nickel have to be used to create alloy that contains 4.9 lb of zinc.
To proof
As given
An alloy consists of nickel, zinc, and copper in the ratio 2:7:9.
the total part of the alloy are 18.
assuming one part be x.
thus
nickel part = 2x
zinc part = 7x
copper part = 9x
alloy that contains 4.9 lb of zinc.
than the equation becomes
7x = 4.9

x = 0.7
Therefore
nickel part = 2x
= 2× 0.7
= 1.4 lb
1.4 lb of nickel have to be used to create alloy that contains 4.9 lb of zinc.
Hence proved