Jacob spent $400 on books. Math books cost $60 and science books cost $50. If he bought a total of 7 books then how many of each kind did he buy?

5 math books and 2 science books.

Step-by-step explanation:

Let's write a system of equations for this. m= math books and s= science books.

The first equation will be about the price.

60m+50s=400

The second will be about the amount he bought.

m+s=7

Let's solve by substitution.

m+s=7 can be rewritten as s=7-m.

Substitute s with 7-m.

60m+50(7-m)=400

60m+350-50m=400

10m+350=400

10m=50

m=5

Then we can plug it into the first equation.

5+s=7

s=2

to plot points   for x just start at the origin (middle) and go to the left however many times it say(if the number is a positive) if the number is a negative then go right however many times it says if it is 0 go nowhere

now keep you pencil there and go up however many times it says on y(if it is positive) if it is negative then go down however many times it says. if it says 0 go nowhere.

you have just plotted a point! now when you finish plotting all of them connect them with a ruler

plot each point as (-3, 7), (0,4), (3,1), (8,-4)   in the parenthesis on the left of the comma is x and the right is y.

circumference divided by 3.141592654 then timesthe radius twice

step-by-step explanation:

circumference divided by 3.141592654 then timesthe radius twice