4 x 7= 28
BTW no calculator. Did it in my head. Hope this helps!
Answer:
0
Step-by-step explanation:
Any number multiplied by zero is equal to zero. So if the product is zero, one factor must be zero. Since you already have a nonzero factor, the other must be zero.
Answer:
Step-by-step explanation:
I think it is 22
Answer: This coil will not be enough to complete the job.
Step-by-step explanation:
The circumference of the coil of wiring can be calculated with:

Where r is the radius and 
The radius can be calculated by dividing the diameter by 2. Then:

Convert 9 inches to yards (1 yard=36 inches):

Substitute this radius into the formula:

Since there are 21 circles of wire, you need to multiply
by 21:

The coil has 32.97 yards of wire and Alex needs 34 yards, therefore, this coil will not be enough to complete the job.