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Solve algebraically: 6a + b = 16 5a - 2b = 19

b= 16-6a this will be your substitution. 5a- 2(16-6a)=19 now multiply out. 5a-32+12a=19 always remember positive and a negative multiplied is a negative. 17a=51 a= 51/17 = 3 now substitute a 6(3) +b = 16 b= -2
JD
Answered by Jade D. • Maths tutor
3629 Views

Solve the quadratic equation x^2-6x+5=0

x 2 - 6x + 5 = 0. For simple quadratic equations such as this example we need to factorise the expression into 2 brackets: (x+a)(x+b) = 0. To find a and b we can expand the brackets to give: x 2 + (a+b)x +ab...
WR
Answered by William R. • Maths tutor
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How do you know when to add probabilities together and when to multiply them together

A probability that an event occurs will always range between 0 and 1. If you want to know the probability of two events both happening you would multiply them together. For exampke what is the probability I ...
PS
Answered by Priyen S. • Maths tutor
6201 Views

A 4kg bag of rice costs £3.20 and a 6kg bag of rice costs £5.80. Which bag of rice is the best value for money? Show all your working.

To work out which bag is best value for money you have to work out the price of each bag per kg. To do this you must divide the price of the bag by the number of kg's it weighs. I.e. 3.20/4 = 80p per kg, 5.8...
YN
Answered by Yasha N. • Maths tutor
4928 Views

How do I factorise a quadratic equation?

To factorise an equation is to put it into (usually two) brackets in the form (x+a)(x+b), where a and b are integers, which multiply out to make the original equation. So whenever you see the word factorise,...
JH
Answered by Juliette H. • Maths tutor
3962 Views