Anonymous
Anonymous asked in Science & MathematicsMathematics · 9 years ago

Pre-Algebra Math Problem ...please work out..STEP BY STEP?

1. 4/13= -2b/13 + 6b/26

2. Alessia is paid 1.4 times her normal hourly rate for each hour she works over 30hrs in a week. Last week she worked 35 hours and earned $436.60. Write and solve an equation to solve Alessia hourly rate. WORK OUT STEP BY STEP.

3. Lydia rode 243 miles in a three-day bike trip. On the first day, Lydia rode 67 miles. On the second day, she rode 92 miles. How many miles per hour did she average on the third day if she rode for 7 hours? WORK OUT STEP BY STEP.

4. -2x - 7 + 3x =10

3 Answers

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  • Al
    Lv 7
    9 years ago
    Favorite Answer

    The common denominator is 26 so in order that 4/13 and 2/13 can also have denominators of 26 you multiply them by 2

    8/26 = -4b/26 + 6b/26 Now that they all have a common denominator you can add the -4b and 6b to get 2b/26

    8/26 = 2b/26 Now you can simply ignore the denominators and solve the top 8 = 2b , b = 4

    4. -2x - 7 + 3x = 10

    add the x's

    -2x + 3x = x so therefore

    x - 7 = 10

    x = 17

  • 9 years ago

    1. Multiply everything by 26 so it looks like:

    26/1*(4/13) = 26/1*(-2b/13) + 26/1*(6b/26)

    After cross simplifying:

    2*4 = (2*-2b) + 6b

    8 = -4b + 6b

    2b = 8

    b = 4

    Number 2...

    x will be her normal rate.

    30x + 5x*1.4 = 436.60

    so 1.4 * 5 = 7

    37x = 436.60

    divide both sides by 37

    x = 11.8

    Number 3....

    243 - 67 - 92 = 84.

    84miles / 7 hours = 12 miles per hour.

    Number 4....

    Combine the xs.

    x - 7 = 10

    x = 17

  • 9 years ago

    I can help on 4.

    -2x - 7 + 3x = 10.

    Combine the x's.

    So:

    x - 7 = 10.

    Add 7 to each side.

    x = 17

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