Answer:
Step-by-step explanation 10 + 2.50d = 850
David starts with $10 and each day he earns $2.50. The d represents a variable and can be any number.
To find d you must solve the equation.
10 + 2.50d = 850
2.50d = 840 (subtract 10 from 850)
d = 336 (divide 840 by 2.50)
It will take David 336 days to save $850.
Step-by-step explanation:
Given
x² - 9x + 20 = 0
x² - ( 4 + 5) x + 20 = 0
x² - 4x - 5x + 20 = 0
x ( x - 4 ) - 5 (x - 4 ) = 0
(x - 4 ) ( x - 5 ) = 0
Either
x - 4 =0
x = 4
or
x - 5 =0
x = 5
x = 4 and 5
Hope it will help :)

Answer:
It will take it 1 and 1/2 hours.
Step-by-step explanation:
Because they walk 5/6 miles in 5/4 hours we can set up a proportion. They walk 1/6 miles in 1/4 hour. Now using the proportion we can find out that they walk 1 full mile or 6/6 of a mile in 6/4 hours or 1 and 1/2 of an hour.
Answer:

Step-by-step explanation:
The given options are:

The key to determining which product is negative is to understand the rule of sign multiplication.
Now:
- The product of even negative terms is positive
- The product of odd negative terms is negative.
- The product of positive will always be positive.
In Options A and B, the number of negative signs is even, therefore our result is positive.
In option C, all the terms are positive, therefore our result will be positive.
In Option D, the number of negative signs is odd, therefore our result is negative.