Answer:
in step by step
Step-by-step explanation:
Phosphorus - 15-2-8-5
magnesium 12-2-8-2
argon 18-2-8-8
silicon 14-2-8-4
'of' can be translated into multiply so
9/10 of 90=9/10 times 90
90=90/1
9/10 times 90/1=(9 times 90)/10=810/10=81/1 times 10/10=81
Answer: x = 1, y = 1
Step-by-step explanation:
Step 1: Solve for x
Multiply bottom equation by 2.
5x + 2y = 7
2(3x – y = 2)
___________
5x + 2y = 7
+ 6x - 2y = 4
___________
11x = 11 divide each side by 11 x = 1
Step 2: Solve for y
Substitute x=1 into any equation. We will do equation 1.
5x + 2y = 7 5*1 + 2y = 7
5 + 2y = 7
subtract 5 from each side.
2y = 2 divide each side by 2
y = 1
what do you need to know the percentage he would be paying back
Answer:
n = 20
Step-by-step explanation:
The problem says that there is a number (n) that is added to 1/5 of itself ((1/5)*n), and that sums is equal to 24, so the equation that models the problem is:
n + (1/5)*n = 24
Taking the least common multiple in the left side, which is 5:
(5n + n)/5 = 24
6n = 120
n = 120/6
n = 20