Refresh myself in one step equation 31=48+x

Kevin and randy muise have a jar containing 78 coins, all of which are either quarters or nickels. the total value of the coins in the jar is $13.90. how many of each type of coin do they have?

The fraction of defective integrated circuits produced in a photolithography process is being studied. a random sample of 300 circuits is tested, revealing 17 defectives. (a) calculate a 95% two-sided confidence interval on the fraction of defective circuits produced by this particular tool. round the answers to 4 decimal places. less-than-or-equal-to p less-than-or-equal-to (b) calculate a 95% upper confidence bound on the fraction of defective circuits. round the answer to 4 decimal places. p less-than-or-equal-to

Plot the intercepts to graph the equation