13. for what value of b would the following system of equations have an infinite number of solutions? 9x + 12y = 21
6x + 8y = 7b explain and show steps : )

b=2

Step-by-step explanation:

9x + 12y = 21

6x + 8y = 7b

To have an infinite number of solutions, the two equations must be equal

Take the first equation and divide by 3, since it is a factor of all the terms

9x/3 + 12y/3 = 21/3

3x+4y = 7

Then multiply by 2 to get the x term equal

2*3x + 2*4y = 2*7

6x +8y = 7*2

Comparing this to the second equation

6x + 8y = 7b

b must equal 2

89

step-by-step explanation:

60°

step-by-step explanation:

the measure angle of c in an isosceles triangle abc is 60° because in isosceles triangle,the measures of all the angles is 60°.