Solve the simultaneous equations
2x+y=5
5x+3y=12

x=3 and y= -1

Step-by-step explanation:

Step 1: Solve2x+y=5 for y:

2x+y=5

2x+y+−2x=5+−2x(Add -2x to both sides)

y=−2x+5

Step 2: Substitute−2x+5foryin5x+3y=12:

5x+3y=12

5x+3(−2x+5)=12

−x+15=12(Simplify both sides of the equation)

−x+15+−15=12+−15(Add -15 to both sides)

(Divide both sides by -1)

x=3

Step 3: Substitute3forxiny=−2x+5:

y=−2x+5

y=(−2)(3)+5

y=−1(Simplify both sides of the equation)

x=3 and y=−1

50-38=12

step-by-step explanation:

36 girls

step-by-step explanation:

the 48 boys is 4 parts of the ratio

divide 48 by 4 to obtain one part of the ratio

= 12 ← 1 part of the ratio

3 parts = 3 × 12 = 36 ← number of girls