Solve the simultaneous equations. (1) 2x + y = 18 (2)x − y = 6
In these simultaneous equations, there are two unknowns. The first is x, the second is y. The aim of a question like this is to find what x and y are equal too. A method to doing this is to rewrite one equations to make one of the unknowns the subject of the equations (This means that x or y will be after the equals sign alone, for example x-6=y). This would then be followed by substituting this into the other equations (the one you didnt use) to then give an equation with only one unknown.
Example Answer: taking (2) rearrange x-y=6 to equal x-6=y x-6 is the same as y, so rewrite equation 1 but write that instead of y 2x+y = 18 2x + x - 6 = 18 2x + x = 24 3x = 24 x= 8
SW
Related Maths GCSE answers
All answers ▸P has coordinates (3,4), Q has coordinate (a,b), a line perpendicular to PQ has equation 3x+2y=7. Find an expression for b in terms of a
ABC and BCD are two attached triangles, attached along line BC. AB = 5.8cm, AC=5.2cm, BD=4.3cm. Angle BDC = 30 degrees, and angle DCB is a right angle. Calculate angle CBA.
Julia wants to buy a new computer. 20% VAT is added to the price of the computer so that she now has to pay £300. What was the original price of the computer without VAT.
How to convert a recurring decimal into fraction