Heather writes the equations below to represent two lines drawn on the coordinate plane.
–6x + 18y = 0
4x – 12y = 20

after applying the linear combination method, heather arrived at the equation 0 = 60. what conclusion can be drawn about the system of equations?

a) the equation has no solution; therefore, the system of equations has no solution.
b) the equation has a solution at (0, 60); therefore, the system of equations has a solution at (0, 60).
c) the equation has infinite solutions; therefore, the system of equation as infinite solutions.
d) the equation has a solution at (0, 0); therefore, the system of equations has a solution at (0, 0).

Atechnician compares repair costs for two types of microwave ovens (type i and type ii). he believes that the repair cost for type i ovens is greater than the repair cost for type ii ovens. a sample of 6767 type i ovens has a mean repair cost of $79.79$⁢79.79. the population standard deviation for the repair of type i ovens is known to be $19.18$⁢19.18. a sample of 5555 type ii ovens has a mean repair cost of $75.24$⁢75.24. the population standard deviation for the repair of type ii ovens is known to be $21.40$⁢21.40. conduct a hypothesis test of the technician's claim at the 0.050.05 level of significance. let μ1μ1 be the true mean repair cost for type i ovens and μ2μ2 be the true mean repair cost for type ii ovens. step 2 of 4 : compute the value of the test statistic. round your answer to two decimal places.