Problem page
a textbook store sold a combined total 217 of history and chemistry textbooks in a week. the number of chemistry textbooks sold was 57 less than the number of history textbooks sold. how many textbooks of each type were sold?

Amira is told there is a trick to finding the slope within an equation in standard form,  ax+by=c. she is told she can rewrite this equation in slope-intercept form,  y=mx+b,  to find the pattern. she correctly rewrites the equation  7x+9y=14  in slope-intercept form as  y=−79x+149.which answer explains the pattern for how to find the slope using an equation in standard form? a. in slope-intercept form, the slope is  −79.these values are  a  and  b,  but with the opposite sign, so the slope of the line from the equation in standard form is  −ba. b.in slope-intercept form, the slope is  −79.these values are  a  and  b,  but with the opposite sign, so the slope of the line from the equation in standard form is  −ab. c.in slope-intercept form, the slope is  149..  these values are  c  and  a, but with the opposite sign, so the slope of the line from the equation in standard form is  −ca. d.=in slope-intercept form, the slope is  149.  these values are  c  and  b,  but with the opposite sign, so the slope of the line from the equation in standard form is  −cb.