Originally Posted by
Raiyne
What the, how old are you guys? In Singapore we learnt this last year in our 8th Grade, 14 years old. o_O This year all our maths involves algebra lol...
K what you need to do everytime is to make x the subject, that is, to make it alone. First you just make one of the variables alone and substitute it into the other equation, so the equation will only have one variable then you can just bring the numbers over and solve it.
For example:
y = 2x + 5 - first equation (1)
y = 3x - 5 - second equation (2)
Sub (1) into (2)
2x + 5 = 3x - 5
Bring 2x from the left to the right, so it'll become -2X
5 = 3x - 2x - 5
5 = x - 5
Bring -5 to the left so when it moves over the '=' sign it will become +5 right?
10 = x - third equation (3)
Sub (3) into (1)
y = 2(10) - 5
y = 20 - 5
y = 15
Voila solved.
y = 2x
y = 3x - 2
Just substitute the first one into the second equation so you'll have
2x = 3x - 2
bring 2x over
0 = x - 2
bring 2 over
x = 2
Donez!
y = x
y = 2x - 4
x = 2x - 4
0 = x - 4
x = 4
Have fun with algebra! lol...
