2x+y=-11; 3x-4y=11

How do I solve this by substitution?

Isabel deposits 6000 into an account that earns 1.5% interest compounded monthly. assuming no more deposits and no withdrawals are made, how much money is in the account after 4 years

Box A is 567 inches high, 678 inches wide, and 789 inches long. It has a maximum capacity of 1,200 marbles, Box B has three times the height, four times the width, and the same length as Box A. What is the maximum capacity of Box B?

Leo has 100 coins in his piggy bank. All coins are either nickels, or dimes, or quarters. There are as many nickels as dimes and quarters together. How much money are nickels in Leo's piggy bank worth?

What is the anwser to (2a - 6) (3a + 15) = 0

The first six triangular numbers (1,3,6,10,15, 21) are printed once each on one side of a card. the cards are placed face down and mixed. choose two cards at random, and let x be the sum of the two numbers.

Turn 18 2/5 into a decimal

you invest $80 at a simple annual interest rate of 2.4% how much simple interest would you earn in 1.5 years. what would the monthly interest rate need to be to earn the same amount of intersest during the same amount of time?

What is 2.25 as a fraction

Suppose that two cards are randomly selected from a standard? 52-card deck.? (a) what is the probability that the first card is a clubclub and the second card is a clubclub if the sampling is done without? replacement??

In 5 h, you drive 400km. how much km could you drive in 1 h.