1.5r+15=2.25r
Combine like terms: 1.5r+15-1.5r=2.25r-1.5r
15=0.75r
Get the unknown alone: 15/.75=.75/.75r
20=r or r=20 :)
1) 5t^2 (1 + 6t)
2) 4x^3y^5 (5x + 2y)
3) (5r + 6x)(5r - 6x)
4) (x + 10)(x - 10)
5) (x - 3)^2
6) (x -5)(x - 3)
7) 3(16r^3 + 9)
8) 8(c^3 + 8d^3)
9) (2r - 125)(4r^2 + 250r + 15625)
10) (c + 3)(c - 1)
Here we are finding x, given the angle and adjacent side. To find x we will use the function cos as cos = a/h.
So let's do cos(35°) = 15cm / x
cos(35°) = 0.8 (1 dp)
x = 15 cm / cos(35°)
x = 18.3 cm (1 dp)
