7\5x-9.42-2\5x-1.58 combine like terms

Can someone show me the steps to solve the problem?

The larger of two number is 4 less than twice the smaller number. the sum is 41. find the numbers

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