(x+3) + (4x-1) find the sum

Ineed with math stuff it involves graphs

Asporting good store is offering 30 percent off of the original price(x) of football cleats. the discount will be reduced by an another $7 before sales tax.

Which of these statements is correct? the system of linear equations 6x - 5y = 8 and 12x - 10y = 16 has no solution. the system of linear equations 7x + 2y = 6 and 14x + 4y = 16 has an infinite number of solutions. the system of linear equations 8x - 3y = 10 and 16x - 6y = 22 has no solution. the system of linear equations 9x + 6y = 14 and 18x + 12y = 26 has an infinite number of solutions.