Answer:
x = -1 and x = 4
Step-by-step explanation:
Step 1: Get everything to one side of the equation so it's set equal to zero..
-x² + 4x = x - 4 becomes...
-x² + 3x + 4 = 0 (subtract x and add 4 to both sides)
x² - 3x - 4 = 0 (divide both sides by -1, we want the x² term to be positive)
(x - 4)(x + 1) = 0 (factor)
so
x - 4 = 0, then x = 4
and
x + 1 = 0, then x = -1
Answer:
square units
Step-by-step explanation:
To predict the area of the piece of paper after 5 tears we can use a geometric sequence.
Each time a piece is torn, half of the previous area is lost. If the area of the first piece is 1 square unit then:

square units
Answer:
4/9
Step-by-step explanation:
Ratio of boys = 4
Ratio of girls = 5
1. When illustrating ratios in fraction, you add the ratios
4 + 5 = 9
2. Next you put the boys ratio over the total ratio
4/9
3. Sometimes it can be reduced to a lower form eg. 5/10 can be reduced to
1/2.