Combine the like terms in the expression. drag the item from the item bank to its corresponding match. −12x4 + 7x3 + 6x4 − 2x3 add answer −5x3 + 7x4 + 4x4 − 8x3 add answer −2x4 − 10x3 + 4x4 − 2x3 add answer 15x3 − 15x4 + 13x4 − x3 add answer 7x4 − 15x3 + 12x3 − 2x4 add answer11x^4 − 13x^3 14x^3 − 2x^4 2x^3 − 12x^3 5x^3 − 6x^4 5x^4 − 3x^3 don't guess!

Farmers know that driving heavy equipment on wet soil compresses the soil and injures future crops. here are data on the "penetrability" of the same type of soil at two levels of compression. penetrability is a measure of how much resistance plant roots will meet when they try to grow through the soil. compressed soil 2.85 2.66 3 2.82 2.76 2.81 2.78 3.08 2.94 2.86 3.08 2.82 2.78 2.98 3.00 2.78 2.96 2.90 3.18 3.16 intermediate soil 3.17 3.37 3.1 3.40 3.38 3.14 3.18 3.26 2.96 3.02 3.54 3.36 3.18 3.12 3.86 2.92 3.46 3.44 3.62 4.26 use the data, omitting the high outlier, to give a 95% confidence interval for the decrease in penetrability of compressed soil relative to intermediate soil. compute degrees of freedom using the conservative method. interval: to