D+Q=61 => D=61-Q
3+D=Q
10D+25Q=1090
10(61-Q) + 25Q=1090
610-10Q+25Q=1090
610+15Q=1090
-610 -610
15Q=480
480/15=32
32 quarters
The LCM for 4 and 9 is 36
• There is a 7 centimeter difference
• They both have 10 centimeters
• They are both made out of string
• They both use centimeters
Answer:
x=1, y=7
Step-by-step explanation:
y = -3x + 10 - first equation
y=-3x + 4 - second equation
rearrange the expression to
-3x-y= -10
3x-y= -4
pick an equation and simplify; lets pick the second equation
3x-y= -4
divide 3 by both sides
x=
- third equation
substitute the value of x into an equation; lets pick the first equation
-3x-y= -10
-3
- y = -10
simplify. -3 cancels 3 so we are left with
-1(-4+y)-y = -10
simplify
4-y-y= -10
4-2y= -10
subtract 4 from both sides
-2y= -10-4
-2y= -14
divide -2 by both sides
y=7
substitute the value of y, (y=7) in an equation, we are using the second equation
3x-y= -4
3x-7= -4
3x = -4+7
3x= 3
divide 3 by both sides
x=1
so the answer is x=1, y=7