Solve, using the substitution method. y – 3x = 7 21 + 9x = 3y A. There is no solution. B. There are an infinite number of solutions. C. The solution is (1, 10) D. The solution is (28, 0)
The answer is B let me show my answer -3x+y=7;9x+21=3ySolve -3x+y=7 for y Add 3x to both sides -3x+y+3x=7+3xy=3x+7Substitute 3x+7 for y in 9x+21 =3y9x+21=3y9x+21=3(3x+7)Simplify both sides of the equation 9x+21=9x+21Add -9x to both sides 9x+21+-9x=9x+21+-9x21=21Add -21 to both sides 21+-21=21+-210=0 Answer : B , Infinitely many solutions I hope that's help ! Have a great day !