Need these in 10 mins: Solve by substitutions
1) X+Y=6
3x+2y=15
2 2x+Y=20
3) 6x-SY=r

In the diagram, the ratio of ab to ae is (1/2) . what is the ratio of the length of to the length of ?

A33 gram sample of a substance that's used to detect explosives has a k-value of 0.1473. n = noekt no = initial mass (at time t = 0) n = mass at time t k = a positive constant that depends on the substance itself and on the units used to measure time t = time, in days

Jada has a meal in a restaurant she adds up the prices listed on the menu for everything they ordered and gets a subtotal of $42.00. when the check comes, it says they also need to pay $3.99 in sales tax. what percentage of the subtotal is the sales tax