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How can you factorise x^2-9

First, we notice how there is only an 'x²' term and a number in this expression. Also notice that the number, 9, is a square number. Whenever you have an expression that looks like 'x²

Answered by Rebecca A. • Maths tutor

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Solve the simultaneous equations 6x - 27 = 15 and 4x + 3y = -3.

Initially we have two unknown variables, so we want to eliminate one of the variables (x) to solve for the other (y). The LCM of 6 and 4 is 12, so multiply each equation such that the coefficient of x is ...

Answered by Alannah C. • Maths tutor

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Given the ratio of x : y is 7 : 4 and x + y = 88. Work out the value of x – y

7x = 4yx=4y/7If we insert this into our other equation.4y/7 + y = 8811y/7 =88y = 56As we knowx =4y/7X= 4*56/7 = 32Then we can work out the answer X - Y = 32 - 56 = -24

Answered by Salih K. • Maths tutor

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Solve the following simultaneous equations: x^2 + y^2 = 29 and y - x =3

This question is slightly trickier than normal simultaneous equations, because we have values to the power of 2. What we can do is make either y or x the subject of the 2nd equation (y-x = 3). For this ex...

Answered by Trushna D. • Maths tutor

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There are 48 girls in a large cheerleading squad. The ratio of girls to boys in this squad is 8:3. How many boys are in the squad?

There are (48/8)*3=18 boys. Since the ratio of boys to girls is 8:3 you divide the number of girls by 8 which gives 6 and then multiply by 3 to give the number of boys.

Answered by George H. • Maths tutor

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