The value of x in this system of equations is 1.
3x + y = 9
y = –4x + 10
substitute the value of y in the first equation:
combine like terms:
apply the subtraction property of equality:
apply the division property of equality:
3x + (–4x + 10) = 9
–x + 10 = 9
–x = –1
x = 1
what is the value of y?

Ascientist has 50 grams of a radioactive element. the amount of radioactive element remaining after t days can be determined using the equation (1) after two days the scientist receives a second shipment of 50 grams of the same element. the equation used to represent the amount of shipment 2 remaining after t days is 10) - 50 which of the following is an equivalent form of the expression for the amount remaining in shipment 2? what’s the answer?