Without using a calculator, give an estimate for the square root of 67. Give a reason for your answer.
The square root of 67 is between 8 and 8.5 as the two square numbers we know are 64 and 81.
Here are two simultaneous equations 2a - 5b = 11 3a + 2b = 7 Which method would you use to solve them, elimination or substitution and why?
Elimination is more appropriate as neither unknown variable has a coefficient of 1. Therefore if we rearrange x= or y= we will have to work with fractions or decimals. By multiplying the first equation by 3 and the second by two we can make the coefficients of a both 6 and easy to eliminate by subtracting the two equations.