MaxWong

x-15% = 100

x = 100+15%

   = 100 + 3/20

   = 2003/20

   = 100.15

Sine is $\frac{opposite}{hypotenuse}$

Cosine is $\frac{adjacent}{hypotenuse}$

Tangent is $\frac{opposite}{hypotenuse}$

Take logarithms on both sides

log 0.254 = X log 0.5

Therefore X = log 0.254 / log 0.5 ≈ 1.977099598.........

600 + 14.36%

= 600 + 0.1436

= 600.1436

3^4=81

x/(x-7) = y

x = y(x-7)

x = xy-7y

x-xy = -7y

xy-x = 7y

x(y-1) = 7y

x = 7y/(y-1)

72 * 3 = 216

Calculators are always your best friend

any number except 0 to the power of 0 is 1

because $0^0 = 0{}^{-0}=1/0^0 = infinity$

2^0 = 1

$(a+1)(a+2)=(a)(a+2)+1(a+2)=(a)(a)+2a+a+2=a^2+3a+2$