Question

*WILL MARK BRAINLIEST*

Answer 1

The text itself determined how to solve the problem.

Namely, two object are given in two relations and we conclude that we have two variables that we present with two equations.

We will take hardcover books as x and paperbacks as y.

First equation is  4x+10y=64

Second equation is  5x+7y=58

This is system of two linear equations with two variables

To solve this system we will use Gaussian agorithm with which we make

gradual elimination of the variables.

We will multiply first equation with number 4 and second with number (-5)

and get

20x+50y=320   and   -20x-28y=-232

When we add first equation to another we get

variable x is eliminated  

50y-28y=320-232 => 22y=88 => y=88/22=4

y=4  when we replace variable y in the first equation before multiplying

we get  4x+10*4=64 => 4x+40=64 => 4x=64-40 => 4x=24 => x=24/4=6

x=6

Total charge for hardcovers is  => 4x+5x=9x=9*6=54$

Total charge for paperbacks is => 10y+7y=17y=17*4=68$

Good luck!!!

Answer 2

Answer:

The text itself determined how to solve the problem.

Namely, two object are given in two relations and we conclude that we have two variables that we present with two equations.

We will take hardcover books as x and paperbacks as y.

First equation is  4x+10y=64

Second equation is  5x+7y=58

This is system of two linear equations with two variables

To solve this system we will use Gaussian agorithm with which we make

gradual elimination of the variables.

We will multiply first equation with number 4 and second with number (-5)

and get

20x+50y=320   and   -20x-28y=-232

When we add first equation to another we get

variable x is eliminated  

50y-28y=320-232 => 22y=88 => y=88/22=4

y=4  when we replace variable y in the first equation before multiplying

we get  4x+10*4=64 => 4x+40=64 => 4x=64-40 => 4x=24 => x=24/4=6

x=6

Total charge for hardcovers is  => 4x+5x=9x=9*6=54$

Total charge for paperbacks is => 10y+7y=17y=17*4=68$

Good luck!!!

Step-by-step explanation: