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Expand and Simplify (5x - 2y)^2

We can rewrite this as (5x - 2y)(5x - 2y). Now all we have to do is expand the brackets. We can do this by multiplying all the terms in the second bracket by all the terms in the first bracket and then sum t...
RM
Answered by River M. • Maths tutor
6527 Views

A family go into a shop, they buy three sandwiches and two packets of crisps. It costs them £9. Another family buy five sandwiches and six packets of crisps. It costs them £19. How much does two sandwiches and five packets of crisps cost?

We will call sandwiches S and packets of crisps C. These are the 'unknowns'. From the information we can write down two equations. Equation 1: 3S + 2C = 9 and Equation 2: 5S + 6C = 19. We need two equations ...
SS
Answered by Sharmi S. • Maths tutor
3432 Views

Find all solutions to the equation: 2x^2+3x-27=0

Firstly, factorise. (2x + 9) (x - 3) = 0 2x + 9 =0 x-3 = 02x = -9 x = 3 x = -9/2
SS
Answered by Sharmi S. • Maths tutor
1891 Views

A ball, dropped vertically, falls d metres in t seconds. d is directly proportional to the square of t. The ball drops 45 metres in the first 3 seconds. How far does the ball drop in the next 7 seconds?

If d is directly proportional to the square of t, we write this as d= kt 2 , where k = the proportionality constant which we must find. Substitute in the values given in the question into our equation to get...
KL
Answered by Katie L. • Maths tutor
22750 Views

A curve has parametric equations x= 2sin(t) , y= cos(2t) + 2sin(t) for -1/2 π≤t≤ 1/2π , show that dy/dx = - 2sin(t)+ 1

A parametric equation is where both x and y are expressed separately, in terms of a parameter (t). In order to differentiate them we must use the chain rule, which here would be dy/dx= dy/dt ÷ dx/dt. The dif...
KL
Answered by Katie L. • Maths tutor
15689 Views