The cost of 3 pencils and 2 markers is $1.30. The cost of 2 pencils and 3 markers is $1.20.
What is the total cost of 7 pencils and 7 markers?

$3.50

Step-by-step explanation:

Given that the  cost of 3 pencils and 2 markers is $1.30. Let the cost of  a pencil be $p and that of a marker be $m then

3p + 2m = 1.30

Also, the cost of 2 pencils and 3 markers is $1.20 will result

2p + 3m = 1.20

Solve both simultaneously

3p + 2m = 1.30

2p + 3m = 1.20

multiply the first by 2 and the second by 3

6p + 4m = 2.60

6p + 9m = 3.60

subtract the second from the first

4m - 9m = 2.60 - 3.60

-5m = -1

Divide both sides by -5

m = 0.20

substitute into equation 1

3p + 2(0.2) = 1.30

3p + 0.4 = 1.30

3p = 1.30 - 0.40

3p = 0.90

Divide both sides by 3

p = 0.30

The total cost of 7 pencils and 7 markers

= 0.30 * 7 + 0.20 * 7

= 2.10 + 1.40

= $3.50

none.

step-by-step explanation:

m

1

=

5

m1=5

b

=

−

1

b=-1

find the slope and y-intercept of the second equation.

tap for more

m

2

=

0

m2=0

b

=

−

6

b=-6

compare the slopes

m

m of the two equations.

m

1

=

5

,

m

2

=

0

m1=5,m2=0

compare the two slopes in the decimal form. if the slopes are equal, then the lines are parallel. if the slopes are not equal, then the lines are not parallel.

m

1

=

5

,

m

2

=

0

m1=5,m2=0