Answer:
The mean number of children is 3.
Step-by-step explanation:
Multiply first equaton by -1 and add to first
-2x+y=7
<u>4x-y=-4 +</u>
2x+0y=3
2x=3
divide 2
x=3/2
sub
2x-y=-7
2(3/2)-y=-7
3-y=-7
minus 3
-y=-10
negative 1 times both sides
y=10
(3/2,10)
(1.5,10)
B is ansre
Let the cost of 1 notebook be x and the cost of 1 binder be y.
4 notebooks and 3 binders would cost 23.5
Therefore, 4x + 3y = 23.5 (1)
7 notebooks and 6 binders would cost 44.5
Therefore, 7x + 6y = 44.5 (2)
Multiply the first equation by 2.
8x + 6y = 47 (3)
(3) - (2) gives
x = 2.5
Substitute the value of x in (1), we get,
4(2.5) + 3y = 23.5
10 + 3y = 23.5
3y = 23.5 - 10
3y = 13.5
y = 13.5/3
y = 4.5
Hence, cost of 5 notebooks and 3 binders is:
5x + 3y = 5(2.5) + 3(4.5)
= 12.5 + 13.5
= 26
Hence, cost of 5 notebooks and 3 binders is $26.
Answer:
y=x-4
Step-by-step explanation:
The slope is given by
m = (y2-y1)/(x2-x1)
m = (1--9)/(5--5)
m = (1+9)/(5+5)
= 10/10
= 1
The slope is 1
We have the slope and a point,so we can use point slope form
y-y1 = m(x-x1)
y-1 = 1(x-5)
y-1 = x-5
Add 1 to each side
y-1+1 = x-5+1
y=x-4
This is slope intercept form (y= mx+b)
Answer:
28 miles per hour
Step-by-step explanation:
133 miles/285 minutes = 133 miles/4.75 hours = 28 miles/hour
