12.5 / 100 = 20 / X
multiply 100 x 10 to get 2000
multiply 12.5 x X to get 12.5X
divide both 2000 and 12.5X by 12.5 to get 2000 / 12.5 = X
2000 / 12.5 = 160 therefore X = 160
check your answer by multiplying 0.125 by 160 to get 20
First you would do 185-57 which gets you 128 next divide it by 2 which gets you 64 so Angelo has 64 and Dean has 121 stamps and together they have a total of 185
Answer:
x= -3
y= 1
z= 4
Step-by-step explanation:
Please see the attached pictures for the full solution.
*I evaluated the determinants using Sarrus' rule (see last picture):
∆= aei +bfg +cdh -gec -hfa -idb
*The symbol '∆' (delta) is usually used to denote a determinant.
1) expand csc and cotx identity
(1/sinx)-sinx = (cosx/sinx)*(cosx)
2) get common denominator on the left side
(1-sin^2x)/(sinx)= (cos^2x)/sinx
3) using cos^2x+sin^2x=1 you finished
cos^2(x)/sinx= cos^2(x)/sinx
hope that helps<span />
