Respuesta :

Answer:

a=5, s=3

Step-by-step explanation:

a=adult s=student

then write 2 equations to represent the amount of people and money

a+s=8

7.25a+5.5s=52.75

• To solve a pair of equations using substitution, first solve one of the equations for one of the variables. Then substitute the result for that variable in the other equation.

{a+s=8, 7.25a+5.5s=52.75}

• Choose one of the equations and solve it for a by isolating a on the left hand side of the equal sign.

a+s=8

• Subtract s from both sides of the equation.

a=−s+8

• Substitute −s+8 for a in the other equation, 7.25a+5.5s=52.75.

7.25(−s+8)+5.5s=52.75

• Multiply 7.25 times −s+8.

−7.25s+58+5.5s=52.75

• Add −29s/4  to 11s/2.

−1.75s+58=52.75

• Subtract 58 from both sides of the equation.

−1.75s=−5.25

• Divide both sides of the equation by −1.75, which is the same as multiplying both sides by the reciprocal of the fraction.

s=3

• Substitute 3 for s in a=−s+8. Because the resulting equation contains only one variable, you can solve for a directly.

a=−3+8

• Add 8 to −3.

a=5