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

6a + b = 16 (1)

5a - 2b = 19 (2)

(1) x 2: 12a + 2b =32

(1) + (2): 12a + 2b + 5a - 2b = 32 + 19 = 51

17a = 51

a = 51 / 17 = 3

Substitue a = 3 back into (1): (6 x 3) + b = 16

18 + b = 16

b = 16 - 18 = - 2

Substitute a = 3 and b = -2 into (2) to check

(5 x 3) - (2 x - 2) = 19

15 - - 4 = 15 + 4 = 19

NR

Related Maths GCSE answers

All answers ▸

The number of uniform spherical balls that can be produced from a given mass of lead is inversely proportional to the radius of the ball cubed. If 2744 balls can be made when the radius is 1mm, how many balls can be made when the radius is 1.4mm ?


Simplify (x+4)^(2)-(x-2)^(2)


Prove that 0.5757... (recurring) = 19/33. Hence, write 0.3575757... (recurring) as a fraction in its lowest terms.


Prove that the square of an odd number is always 1 more than a multiple of 4