Plz Help I dont understand this. solve for y and x Substitution Method.

1) 2x + 8y = 20 2) x = 5
y = 2 2x + y = 10

Lines a and b are parallel. what is the value of x? -5 -10 -35 -55

Aparticular telephone number is used to receive both voice calls and fax messages. suppose that 25% of the incoming calls involve fax messages, and consider a sample of 25 incoming calls. (a) what is the expected number of calls among the 25 that involve a fax message?

Which equation is y = -6x2 + 3x + 2 rewritten in vertex form?