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Expand the following equations

a. x(x+4)b. 3x(x+4)c. (x+8)(x+3)d. (x+7)^2

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There are 10 boys and 20 girls in a class. In a class test, the mean score of the boys is 77. The mean score of the girls is 80. What is the mean score of the whole class?

To calculate the mean of the whole class:1) Find the sum of the individual scores of the whole class. Boys: 10 x 77 = 770Girls: 20 x 80 = 1600Total of Boys and Girls: 770 + 1600 = 23702) Divide the sum of...

Answered by Anuj M. • Maths tutor

6517 Views

Solve the simultaneous equations: 3x + y = -9, x^2 + 2x - 3 = y

Rearrange the first equation to equal 'y' so y = -9 - 3xSubstitute this into equation 2 so x^2 + 2x - 3 = -9 - 3xRearrange this to equal 0 so x^2 + 5x + 6 = 0Factorise this by utilising brackets so that t...

Answered by Maryum J. • Maths tutor

5660 Views

John left home at 13:55 and reached the shops at 15:20. How long did his journey take?

Work out number of minutes from 13:55 to next hour (14:00) which is 5 minutesCalculate number of whole hours until 15:20 so 1 whole hour = 60 minutesCalculate number of minutes from 15:00 to 15:20 so 20 m...

Answered by Maryum J. • Maths tutor

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