multiply all terms in the second equation by 2 to get the coefficient on the y variable to be -6.

Answer:
There are 60 girls and 40 boys in the class.
Step-by-step explanation:
Given that the mean weight of 100 students in a certain class is 71kg, while the mean weight of boys is 65kg and that of girls is 75kg, to determine what is the number of boys and girls the following calculation must be performed:
1 x 75 + 0 x 65 + 75
0.9 x 75 + 0.1 x 65 = 74
0.8 x 75 + 0.2 x 65 = 73
0.7 x 75 + 0.3 x 65 = 72
0.6 x 75 + 0.4 x 65 = 71
Thus, there are 60 girls and 40 boys in the class.
Answer:
x=5 gg ez
Step-by-step explanation:
Answer:
please help help me me my question
She earns ($9.70x40) for a 40 hour week=$388
She earned $489.85-$388 extra= $101.85
She gets paid $9.7x1.5 for every extra hour=$14.55
She worked $101.85/$14.55 hours extra=7hours
She worked 7+40 hours that week=47 hours