Answer:
a = £4.245, c = £2.455
Step-by-step explanation:
a + c = 6.70
a = c + 1.79
replace a in the first equation with c + 1.79
c + 1.79 + c = 6.70
simplify: 2c + 1.79 = 6.70
subtract 1.79 from each side: 2c = 4.91
divide each side by 2: c = 2.455
now replace c in the second equation with 2.455
a = 2.455 + 1.79
add: a = 4.245