Question

Algebra 2- Solutions by addition.

R-9S=2

3R-3S=-10

A. {(-4, -8/3)}

B. {(-4, -3/2)}

C. {(-4, -2/3)}​

Answer 1

Solve $R-9S=2$ and $3R-3S=-10$ is option C

Definition:

The solution of an equation is the set of all values that, when substituted for unknowns,make an equation true.

Step-by-step explanation:

[tex]R-9S=2\\ [/tex]          (1)

$3R-3S=-10$     (2)

Multiply equation (1) by 3

$3R-27S=6$      (3)

Subtract (2) and (3)

[tex]3R-3S=-10\\ 3R-27S=6[/tex]

(-)    (+)        (-)

___________

[tex]24S=-16\\ S=-\frac{16}{24}\\ S=-\frac{2}{3} [/tex]

Substitute $S=-\frac{2}{3}$ in equation (1)

[tex]R-9S=2\\ R-9(-\frac{2}{3})=2\\ R+6=2\\ R=2-6\\ R=-4[/tex]

Therefore ,the value of R is -4 and S is -2/3 that is option C