Answer:
x = 75
Step-by-step explanation:
Given information from the question:
x - 3y = 30
y = 15
We can substitute y = 15 into the equation to find x.
x - 3(15) = 30
x - 45 = 30
x - 45 + 45 = 30 + 45
x = 75
Answer:
x = 13.444 ... (repeating decimal) or;
x = 13 4/9
Step-by-step explanation:
-0.65 + 0.45x = 5.4
First we will add 0.65 to each 'side' of the equation.
0.65 + (-0.65) + 0.45x = 0.65 + 5.4
0.65 + (-0.65) = 0
0.65 + 5.4 = 6.05
Input the numbers, and now the equation looks like this:
0 + 0.45x = 6.05
Remove the zero:
0.45x = 6.05
Divide each 'side' by 0.45.
0.45x ÷ 0.45 = 6.05 ÷ 0.45
0.45x ÷ 0.45 = 1x = x
6.05 ÷ 0.45 = 13.444 ... repeating decimal
Input the numbers, and now the equation looks like this:
x = 13.444 ... repeating decimal
We can also write this as:
x = 13 4/9 in fraction form
D.8
A and C are out because they would get you ether lower or equal to 20, which is equal to AC and your trying to find X in AB which is so posed to be the what equals AC+BC.
AB=AC+BC
5x=20+BC
5(8)=20+BC
40=20+BC
40=20+20
AC equals 20. AB will have to equal AC+ CB. If you put in A.4 in AB 5X you will get twenty and that not what you want. You want to get a number that will get you the an answer greater to AC. So 5(8)=40.
X + y = 1
x + 3y = 9
Subtract the second equation from the first.
-2y = -8
divide both sides by -2
y = 4
Plug 4 back into either equation and solve for x.
x + y = 1
x + 4 = 1
subtract 4 from each side
x = -3
(-3, 4)
