Which of the following pairs of numbers contain like fractions

Before simplifying, how many terms are there in the expression 2x - 5y + 3 + x?

which of the following sets of data would produce the largest value for an independent-measures t statistic? the two sample means are 10 and 20 with variances of 20 and 25 the two sample means are 10 and 20 with variances of 120 and 125 the two sample means are 10 and 12 with sample variances of 20 and 25 the two sample means are 10 and 12 with variances of 120 and 125

What number is 7 units left of -15?