+21 Guys, I really want to get a A on my maths exam. I am currently in year 10. What do you guys think is the best revision/method to getting that A? I am currently going through past papers
Solve algebraically the simultaneous equations
x2 + y2 = 25
y – 3x = 13
+367 Alright Lewis, we can do this.
We can use the equation y - 3x = 13 and turn it into y = 3x + 13.
We subsitute it for y in the top equation.
This gives us x2 + (3x+13)(3x+13)=25
x2+9x2+39x+39x+169=25
10x2+78x+169=25
10x2+78x+144=0
5x2+39x+72=0
Using the quadratic formula we get
x=-3, -24/5
We can then test these numbers(They work).
After substituting the x back in, y values are 4, -7/5
YEETUS
(My first problem :))
