<span>Total mass contains 320g copper. How many parts of 16g copper are there of the total mass of 320g copper? 320/16 = 20. There are 20 portions of 16g copper.
(320/16) * 3 = 60g
There are 60g of zinc in the compound.</span>
we will check each options
option-A:
For solving any equations , we always isolate variables on anyone side
For exp: x+7=1
so, this is TRUE
option-B:
For solving system of equations
For exp:
x-y=1
x+y=3
If we use addition , we could easily solve for x and y
so, this is TRUE
option-C:
We always solve problems using conventional method
we do not guess
so, this is FALSE
option-D:
We often reverse order of operation
For exp:
(x-2)^2-3=0
so, this is TRUE
option-E:
For linear equations , we always get one solution , infinite solutions or no solutions
so, this is FALSE
Answer:
Due to there being no negatives in this equation, you can pretty much just eliminate the first 3 answers.
However in working out, here is what I did.
x^2 + x - 30 = 12 (+30)
= x^2 + x = 42
Then you can conclude that the answer is D, due to 6 x 6 = 36, plus 7 equaling 42.
I need to know the rest of the question in order to help you! :D
[(21 + 6) − 3^2] ÷ 9 ⋅ 2=[(27) − 9] ÷ 9 ⋅ 2
=18 ÷ 9 ⋅ 2
= 2 . 2
= 4
