Homework

Name ______________

  1. A jar has red and blue marbles. There are a total of 30 marbles in the jar. There are twice as many red marbles as blue marbles. How many blue marbles are in the jar?
    Use B for the number of blue marbles and R for the number of red marbles.
    1. The expression for "there are twice as many red marbles as blue marbles:
        _________________
    2. Write the equation for "the total number of marbles in the jar is 30"
        _________________
    3. Substitute the expression for R from the first expression into the second one and solve:
        R = ______
        ________________________

        B = ____

  2. Joey has taken 3 math tests and his average is 85. He wants to get an "A" which requires an average of 90 or above. He has one more test. What score does he need on this 4th test to get his "A"?
    Let N3 be the total of his first 3 math tests.
        N3 = ______ (add up the 3 scores)
    Let N be the score he needs on his 4th test for an "A"
    1. Write the equation for "the average of his 4 tests must be 90" using variables N3 and N:

        ___________________

    2. Solve for N = ______

  3. My brother and I collect baseball cards. He has been collecting longer than I have. If you add 40 to my number of cards, and then double it, you get the number of cards my brother has: 612. How many baseball cards do I have?
    Let C be the number of cards I have.
    Write the equation:

        _____________________________
        C = ______

  4. What is the measure of the smallest angle of this triangle?


    Write the equation for all the angles adding to 180o
        ____________________________

        x = _____