Shawn said that in standard notation, 7.142 x 107 will have 7 zeros after the
2 because the exponent is a 7. Is he
correct? Why or why not?

This is incorrect.  

Step-by-step explanation:

You move the decimal 7 places to the right after the 7.  Since 2 is the third digit, you're adding 4 more zeros.

x> 6

step-by-step explanation:

8x+8> 7x+14

8x-7x> 14-8

x> 6

x + y = 90 5x – 10y = 90 90 – 10y = 5x 90 + 10y = 5x

step-by-step explanation:

last month maria hiked the 5-mile mountain trail a number of times and she hiked the 10-mile canal trail several times. let x represent the number of times she hiked the 5-mile trail, and let y represent the number of times she hiked the 10-mile trail. if she hiked a total of 90 miles, which equation can be used to find the number of times maria hiked each trail? x + y = 90 5x – 10y = 90 90 – 10y = 5x 90 + 10y = 5x