Hi, can someone me with this?

solve the system of equations:
y= 2x-4
x= y+1

Aclass consists of 55% boys and 45% girls. it is observed that 25% of the class are boys and scored an a on the test, and 35% of the class are girls and scored an a on the test. if a student is chosen at random and is found to be a girl, the probability that the student scored an ais

How are sas and sss used to show that two triangles are congruent?

The interior angles formed by the side of a hexagon have measures of them up to 720° what is the measure of angle a