Let...
x=the number of red bricks
y=the number of blue bricks
Since she bought a total of 100 bricks... x+y=100.
Because the total cost is $560... 5x+7y=560.
Using these two equations, we can use the substitution method to solve for x and y.
x+y=100 ------------------------> x=100-y
subtract y on both sides
Because x=100-y...
this is x
5x+7y=560 (second equation) equals 5( 100 - y )+7y=560
This equation we created has only one variable so we can solve it.
5(100-y)+7y=560
500-5y+7y=560
2y+500=560
2y=60
y=30 blue bricks
Because x=100-y... x=100-30=70 red bricks.
Answer:
D (last answer)
Step-by-step explanation:
solve and simply
Answer:
Y=t+5
Step-by-step explanation:
Bob starts running...(1)
Bill starts running 5 seconds later...(2)
From (1) and (2) we know that Bob had been running for 5 seconds when Bill started running.
The expression we are looking for is
Y=t+5
Y is the number of seconds Bob has been running
t is the number of seconds Bill has been running
Check the image for the diagram.
Answer:8n-4
Step-by-step explanation:
Answer:
x = 6
Step-by-step explanation:
10x = 5 x 12 = 60
x = 6