Which system of linear equations has a solution of (1, –1)?

Igor stravinsky tires sells approximately 3,760,000 car tires and 1,200,000 truck tires each year. about 47,000,000 care tires and 26,000,00 truck tires are sold each year in the united states. what is stravinsky's market share in each of these two markets (cars and trucks)?

Abarbecue sold 26 hamburgers and hot dogs. hamburgers sell for $3.50 each and hot dogs sell for $2.00 each. if the barbecue made $70 in sales, determine and state the number of hot dogs sold.

What is the value of x in the this question ?