If DE=7x, and DF=9x, what is DE? ​

3× __ -2=15 7 2× __+1=7 5 7× =22 15 5× __+10=2 8 × __+4=20 6 × =10 3 × __+2=8 6 × __+8=8 9 × __+7=20 6

Aplane flies around trip to philadelphia it flies to philadelphia at 220 miles per hour and back home with a tailwind at 280 miles per hour if the total trip takes 6.5 hours how many miles does the plane fly round trip

Asmall business produces and sells balls. the fixed costs are $20 and each ball costs $4.32 to produce. each ball sells for $8.32. write the equations for the total cost, c, and the revenue, r, then use the graphing method to determine how many balls must be sold to break even.