There are 270 students in Year 7 Each student studies one of French or German or Spanish.

Of these 270 students

2

study French

9

the number who study French : the number who study Spanish = 3:7

42 boys study German

Of the students who study German, what percentage are boys?

You must show your working.

arrange the equations with like terms in columns.

analyze the coefficients of x or y.

add the equations and solve for the remaining variable.

substitute the value into either equation and solve.

check the solution.

step-by-step explanation:

5=812a+9+3

step 1: simplify both sides of the equation.

5=812a+9+3

5=(812a)+(9+3)(combine like terms)

5=812a+12

5=812a+12

step 2: flip the equation.

812a+12=5

step 3: subtract 12 from both sides.

812a+12−12=5−12

812a=−7

step 4: divide both sides by 812.

812a /812 = -7/812

a= -1/116

so the answer is

a=   -1/116

2y+y=5

add 2y and y